package com.company.观察者模式;

public class Goods extends Subject{
    private int price;
    public Goods(int price){
        this.price=price;
    }
    public int getPrice(){
        return price;
    }
    public void setPrice(int price){
        int priceVar = price-this.price;//价格的变化量
        this.price=price;
        if (priceVar!=0)this.notifyAllObservers(priceVar);
    }
}
